Some wireless keyboards could be exposed to hacking by people aiming to steal private data transmitted by these devices. Using a new attack labeled ‘KeySniffer’ hackers can eavesdrop on and capture every keystroke made on a wireless keyboard from as far away as 75 meters.

The attack allows hackers to search for victims' credit card information, bank account usernames and passwords, answers to security questions, network access passwords, and any data typed into a document or email. This newly identified vulnerability showed that as many as two-thirds of wireless keyboards in the market implement no encryption while transmitting data, thereby leaving them vulnerable to passive keystroke sniffing. Among the keyboards tested and found vulnerable are even those made by leading companies.

The vulnerable keyboards are detected easily, as the USB dongles they use are always transmitting synchronization packets to let the keyboard find them, whether or not they are in use. That lets a hacker home in on them quickly. The sync packets contain the unique identifier for the keyboard or dongle.

Once a vulnerable keyboard is identified, the hacker uses the identifier to filter wireless transmissions for the keystrokes sent by the target keyboard. Hackers can also use the KeySniffer to inject keystrokes to type remotely on a vulnerable computer, installing malware or stealing data. Currently, none of the affected keyboards can be patched by software updates Higher-end keyboards are usually not vulnerable because they frequently use transceivers that have built-in support for 128-bit AES encryption. Similarly, Bluetooth keyboards are also not susceptible because Bluetooth encrypts all data transmitted over the air.